Cellular communication networks continue to experience rapid growth, with the number of devices connected via such networks forecast to increase substantially in the near future. It is expected that machine type devices (MTDs) will contribute significantly to this forecast increase in connected devices. Machine type devices are autonomous, often very small devices typically associated with equipment or apparatus as opposed to a human user. MTDs use cellular or other types of communication networks to communicate with an application server, which may or may not be comprised within the cellular network. The application server receives information from the MTD and configures the MTD remotely to provide a particular functionality. MTDs represent a subset within the larger category of User Equipment devices (UEs), and may also be referred to as machine to machine (M2M) devices. Applications employing MTDs may facilitate activates in a wide range of service areas, examples of which are set out in table 1 below:
TABLE 1Service AreaMTC applicationsSecuritySurveillance systemsBackup for landlineControl of physical access (e.g. to buildings)Car/driver securityTracking & TracingFleet ManagementOrder ManagementPay as you driveAsset TrackingNavigationTraffic informationRoad tollingRoad traffic optimisation/steeringPaymentPoint of salesVending machinesGaming machinesHealthMonitoring vital signsSupporting the aged or handicappedWeb Access Telemedicine pointsRemote diagnosticsRemote Maintenance/SensorsControlLightingPumpsValvesElevator controlVending machine controlVehicle diagnosticsMeteringPowerGasWaterHeatingGrid controlIndustrial meteringConsumer DevicesDigital photo frameDigital cameraeBook
As may be appreciated from the above examples, many thousands of MTDs may be deployed at a particular location supporting a wide range of MTC applications. Unlike traditional user equipment devices, a large number of such devices will be substantially stationary, and may be powered using mains power supply.
Considerable advances have been made in modernising the supply of mains power, for example through the introduction of Smart Grids and Automated Demand Response Management. Smart Grids are electrical power supply grids that use communication technology to gather and act on information in an automated manner with the goal of improving the efficiency and reliability of energy production and distribution. Automated Demand Response Management is a system allowing communication between energy supplies and consumers, enabling automated response to pricing changes and electrical grid load fluctuations, thus improving the balance between supply and demand in energy production and distribution. Despite such advances, scheduled power outages remain a reality for many energy consumers. In developing economies in particular, where rapidly expanding energy demand frequently outstrips supply, regular power outages are common. In India for example, population 1.2 billion, very few metropolitan locations enjoy 24×7 mains power supply, and for the 65% of the population who live in rural and semi-urban areas, scheduled power outages may be a daily occurrence. Even where mains power is more or less constantly available, grid maintenance work may require temporary interruption of power supply, and meteorological or other factors may lead to precautionary action on the part of energy suppliers to impose power outages at certain times and in certain locations.
Nascent and developing M2M ecosystems, and the communications networks that support them, may be particularly impacted by the scheduled power outages discussed above, with large numbers of M2M devices in a single location going offline, and coming back online, at the same time. As developing economies increasingly adopt networked models of society, industry and commerce, challenges remain in managing the impact that intermittent mains power supply may have upon such activities and the communications networks that support them.